The invention relates to a device used by professionals within the optical and ophthalmic industry to heat dyes to a specific temperature to color plastic lenses.
Within the optical lenses manufacturing industry, it has been a widespread practice to color lenses after manufacture in accordance with the customer's preference. Numerous devices have been used for this purpose, the most common being a type that utilizes a double tank system. The first tank is heated electrically, and a heat transfer medium indirectly heats a tank of dye. The dyes used in this process are prone to crystallization and sediment formation. The double tank system helps with this tendency. Optical dyes are most effective at a narrow temperature range (200-205° F.).